BEIJING—Chinese growth data suggest a nation that has long relied on exports is getting more help from domestic demand—a potential positive for the global economy as Europe grapples with its debt crisis and U.S. growth sputters.

Chinese third-quarter gross domestic product was up 9.1% from a year earlier after 9.5% growth in the second quarter, slightly below analyst expectations of 9.2% growth. Still, the growth rate was generally welcomed by economists who saw it as evidence that China can guide its economy to a soft landing...